Spring unit for mattresses, cushions, and the like



NOV. 11, 1952 P, JOHNSON 2,617,124

SPRING UNIT FOR MATTRESSES, CUSHIONS, AND THE LIKE Filed 001:. 6, 1949 IN VEN TOR.

Patented Nov. 11, 1952 UNITED STATES PATENT OFFIE SPRING UNIT FOR MATTRES'SES, GUSHIQNS, AND THE LIKE Gustave P. Johnson, Waukegan, Ill. Application October 6, 1949, Serial No. H9394 3 Claims. 1

The producers of spring structures, for use with various types of sitting and sleeping furniture, have always striven to achieve that degree of yielding resistance which ensures the maximum comfort to persons differing widely in weights commensurate, however, with acceptability in appearance, durability in service, and reasonableness in cost. Generally, springs of the spiral or hourglass type have been used'for seats, cushions and mattresses for various kinds of such furniture. The problem in producing this ype of spring has been to get such a balance in the weight-resisting fiexibleness of the successively smaller convolutions or coils of the individual springs as would avoid concentration of the weight too quickly and locally on the intermediate, more resistant, and smaller coils with their reduced area of contact with the upholstery. Also, there has been the problem of appropriately tying together the several springs of a spring uni-t so as to secure the desired lateral distribution of varying pressures to which the spring structure is normally subjected.

The main objects of this invention, therefore, are to provide an improved spring unit for seats, cushions, :and mattresses and the like; to provide in a spring unit an improved form of component springs wherein the several convolutions or coils receive more nearly uniform flexing when the spring structure is subjected to weights or pressures than has been possible with spring units heretofore produced; to provide fo the spring unit an improved form and arrangement of the top and bottom interconnecting heiicals which will permit the seat cushion or mattress to afiord a comfortable support for persons of materially differing weights; and to provide an improved spring unit cooperatively embodying the aforesaid features so as to make available a seat, cushion or mattress possessing greater comfort and durability than has been obtainable with similar structures heretofore available.

In the accompanying drawings:

Figure 1 is a side elevation, partly sectional, of a mattress embodying a spring unit constructed in accordance with this invention, the cross-sectional portion indicating the compression that takes place when a concentrated load is applied at a localized point;

Fig. 2 is an enlarged, plan view of a section of a spring unit embodying this invention;

Fig. 3 is a further enlarged side elevational view of an individual spring comprised in this invention, the spring being shown in its fully extended position which is free of a load; and

Fig. 4 is a similar view showing the relative degree of flexing of the several coils of the spring when the spring is subjected to axial pressure.

In a. spring unit embodying this invention a plurality of load sustaining wire springs 5 are arranged in parallel rows within the area of the desired seat, cushion, or mattress, and tied together by wire spring helicals '6.

The springs 5 are of the spiral or hourglass type wherein the successive coils or convolutions from the ends of the spring inwardly are of decreasing diameter.assuming that the term diameter may be appropriately used in defining the spiral character of these coil-s or convolutions. The decrease in the diameter of the successive coils is between one-fourth and oneefifth, preferably close to the latter. In the case of a five-coil spring, this will result in the diameter of the innermost or middle coil I being reduced by less than half the diameter of the end or outermost coils 8 of the spring, the diameter of the intermediate coil-s 9 being graduated proportionately.

As shown in Fig. 4, when a spring coil of this description is subjected to axial pressure, the middlecoil I and the intermediate coils 9 yield at very nearly the same rate as the end coils 8, especially during the earlier stages of spring compression; approximately this same rate of yielding continues through a further compression of the spring 5 until its height is reduced by substantially one-half.

The spring-tying helicals l5 and 6a employed in this improved-spring uni-t, which maybe of a conventional nature, extend along both sides of the structure between the load-sustaining springs 5.

Thelhelicals 6 are wound around the end coils of the springs 5 so as to tie adjacent springs together, as shown at H) in Fig. 2. However, in this structure, as shown in Fig. 3, the helicals 6a along the top side of the structure are heavier gauged and possessed of yielding capacities different from those of the lighter gauged helicals 6 extending along the bottom side of the structure. This difference in yielding may be attained 'by using helicals of difiering pitch, or by wire of d'iflerent tempers or different gage. In the embodiment herein shown the helicals are formed of wire of differing gages, as clearly appears from Figs. 3 and 4. This makes possible accommodating such a spring structure to persons of different weights, or to a different number of persons, o to other circumstances. This accommodation would be effected by so positioning the spring unit that the helicals of the greater or less yielding capacity are disposed at the top or at the bottom of the structure, as the circumstances seem to require. A spring structure of this improved form and arrangement would be covered with a suitable fabric casing ll whereon other covering or upholstery can be applied.

The special features of construction inherent in the present spring unit make possible a reduction in the length of the springs without in any degree impairing the cushioning effect thereof. This reduction may amount to 1" or so in a spring structure of conventional size and capacity. As above noted, the cushioning effect is largely concentrated at the coils toward the end of the springs. Yielding of the springs .in response to a load is afiected by the interconnecting helicals which serve to distribute a localized load over a considerably wider area. Where the helicals are stifier, the distribution of the load is confined to a smaller area, whereas with interconnecting helicals having a greater resiliency the load is distributed over a wider area. As the result, it is possible to utilize on one side of the spring unit a set of interconnecting helicals which are relatively stiff, and on the opposite side thereof another set of interconnecting helicals which are relatively flexible; a load imposed on the spring unit side having the stiffer helicals will be distributed less widely than will the same load if imposed upon the opposite side of the spring unit where the more yieldable helicals are located. This circumstance is relied upon to adapt the spring unit for the support of persons varying widely in weight. For example, for a person weighing close to 200 lbs. the spring unit should be disposed with the stiffer helicals uppermost, and the opposite disposition should be made for a person whose weight is considerably less, say 100 lbs. Not only will the spring unit be better adapted to sustain the weight when so disposed in relation to the load which is to be supported, but much greater comfort will be afforded to the person who is using the mattress, cushion, or seat.

Modifications and variations of the construction herein shown and described may be resorted to without departing from the spirit or coverage of the appended claims.

I claim:

1. A spring structure of the class described,

comprising a plurality of rows of coiled springs, I

a plurality of spring helicals of uniform yielding capacity at the top of the spring structure, a plurality of spring helicals of uniform yield n capacity at the bottom of the spring structure, said spring helicals extending along said rows of springs at the inner and outer sides thereof and 4 connected to the end coils of each spring, the spring helicals at the top and bottom of the spring structure being of different yielding capacities, whereby the opposite sides of said structure yield differently to equal pressures.

2. A spring structure of the class described, comprising a plurality of rows of coiled springs, a plurality of spring helicals of uniform yielding capacity at the top of the'spring structure, a plurality of spring helicals of uniform yielding capacity at the bottom of the spring structure, said spring helicals extending along said rows of springs at the inner and outer sides thereof and. connected to the end coils of each spring, the spring helicals at the top of the spring structure being of heavier gauge material than the spring helicals at the bottom of the spring structure, whereby the top of the spring structure will be less yielding than the bottom of the same and be better adapted to support the weight of a heavy person.

3. A spring structure of the class described comprising a plurality of rows of coiled springs, a plurality of spring helicals of uniform yielding capacity at the top of the spring structure, a plurality of spring helicals of uniform yielding capacity at the bottom of the spring structure, said spring helicals extending along said rows of springs at the inner and outer sides thereof and connected to the end coils of each spring, the spring helicals at the top of the spring structure being of lighter gauge material than the spring helicals at the bottom of the spring structure, whereby the top of the spring structure will be more yielding than the bottom thereof and better adapted to support comfortably a person of light weight.

GUSTAVE P. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 401,287 Lytle Apr, 9, 1889 457,041 Bonnell et al Aug. 4, 1891 639,779 Sharf Dec. 26, 1899 1,275,318 Stevens Aug. 13, 1918 1,387,743 Van Hove Aug. 16, 1921 1,450,686 Klaasse Apr. 3, 1923 1,907,541 Heuer May 9, 1933 1,963,053 Powers June 12, 1934 2,052,325 Travis Aug. 25, 1936 2,192,463 Wesley Mar. 3, 1940 2,257,375 Gleason Sept. 30, 1941 

